JPH10122047A - Jet engine restart method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jet engine restart method and apparatus capable of re-igniting a combustor while maintaining stable flight by providing means for adjusting a bypass ratio. SOLUTION: In the jet engine restart device of the present invention, each of the stationary blades 12s of the stationary blade row 12 has a jet engine 1
Hinge portion 13 extending in the radial direction of
And a fixed portion 15 fixed to the downstream side of the hinge portion 13 so that the flow rate ratio between the core flow 7 and the fan flow 8 is determined. By adjusting, the lower limit of the ignitable region of the combustor 4 is adjusted, the combustor 4 is re-ignited in accordance with the flight speed, and the jet engine 1 is restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for restarting a jet engine stopped during flight of an aircraft.

[0002]

2. Description of the Related Art Generally, a jet engine is configured as shown in FIG. The jet engine 1 includes a fan 2 for taking in air, a compressor 3 for compressing the introduced air (a low-pressure compressor 3a and a high-pressure compressor 3b), a combustor 4 for burning fuel with the compressed air, and a combustion gas of the combustor 4. And a turbine 5 (a high-pressure turbine 5a and a low-pressure turbine 5b) for driving the fan 2 and the compressor 3 by a motor. The compressor 3, the combustor 4, and the turbine 5 constitute a core portion of the jet engine 1, a fan 2 is provided on the upstream side, and a tail cone 6 is provided on the downstream side.
Is provided. The air taken in by the fan 2 is branched into a core flow 7 passing through the compressor 3, the combustor 4, and the turbine 5 (core side) and a fan flow 8 bypassing these and passing through the outer duct 9 side. . FIG. 3 shows a type in which the core stream 7 and the fan stream 8 are separately discharged into the atmosphere, but there is also a type in which the core stream 7 and the fan stream 8 merge on the way. . The core flow 7 and the fan flow 8 are separated by a substantially cylindrical partition wall 10. At the inlet of the fan flow 8, a stationary blade row 11 for rectifying the fan flow 8 into an axial flow is provided. Note that the flow rate of the fan flow 8 to the core flow 7 is generally called a bypass ratio.

[0003]

FIG. 4 shows the relationship among the flight speed, the bypass ratio, and the ignitable region of the combustor of the aircraft equipped with the jet engine described above. In this figure, the vertical axis is k / bypass ratio, the horizontal axis is flight speed,
The hatched portion indicates the ignitable region of the combustor, and the right-downward straight line indicates the lower limit of the ignitable region of the combustor. Vertical axis coefficient k
Is determined by the flight conditions of the aircraft such as the pressure ratio between the fan and the compressor, and is a value unique to the jet engine.

When this aircraft is flying at the flight speed indicated by point A in FIG. 4 and the jet engine is stopped due to unintentional extinguishing of the combustor for some reason or emergency for some engine abnormality When the engine is stopped as a means, the k / bypass ratio does not change, but the flight speed gradually decreases, so that the jet engine moves to an area (for example, point B) that is outside the ignitable area of the combustor. . In the region outside the ignitable region of such a combustor, the air flow rate passing through the combustor is too small to atomize the fuel, and the altitude is high and the air temperature is low. Re-ignition of the combustor is not possible. In addition, recent high bypass ratio,
In a jet engine with a high pressure ratio, the lower limit of the ignitable region of the combustor is high, and it is difficult to ignite at a low flight speed.

In order to reignite the combustor,
It is conceivable to take measures such as increasing the flight speed or decreasing the bypass ratio (that is, moving point B upward). However, it is difficult to increase the flight speed without an altitude penalty when the engine is stopped, and since the conventional jet engine does not have a means for adjusting the bypass ratio, the bypass ratio cannot be reduced. However, if it protrudes from the ignitable region of the combustor, it cannot be returned to that region. In such a case, the engine starter can be restarted by supplying power to the engine starter from another engine or an onboard power source device.However, for the sake of safety, the engine must be restarted without starter assist. Flight speed is specified,
If that requirement is not met, there is a problem.

The present invention has been made to solve such a problem. That is, an object of the present invention is to provide a method and an apparatus for restarting a jet engine which can re-ignite a combustor while maintaining stable flight by providing a means for adjusting a bypass ratio.

[0007]

According to the present invention, a core portion having a compressor, a combustor, and a turbine, an outer duct serving as an outer shell, and air taken in from a fan upstream of the core portion are supplied to the core portion side. A jet engine restart method including a substantially cylindrical partition wall that separates into a core flow that passes through and a fan flow that passes through the outer duct side, and a stationary blade row that is provided between the outer duct and the partition wall and that rectifies the fan flow into an axial flow. Adjusting the flow ratio of the fan flow and the core flow in accordance with the flight speed of the aircraft having the jet engine, and re-igniting the combustor. Is provided.

According to the configuration of the present invention described above, the bypass ratio can be adjusted by adjusting the flow rates of the fan flow and the core flow, so that the jet engine can ignite the combustor even at a low flight speed. Since it does not protrude from the region, the combustor can be re-ignited, and the jet engine can be restarted.

Further, according to the present invention, a core having a compressor, a combustor and a turbine, an outer duct serving as an outer shell, and a core flow passing air taken in from a fan upstream of the core through the core. A substantially cylindrical partition separating the fan flow passing through the outer duct side, and a stationary blade row provided between the outer duct and the partition and rectifying the fan flow to an axial flow,
A restart device for a jet engine, comprising: a stator portion of the stator blade row, a hinge portion extending in a radial direction of the jet engine, and a movable portion rotatably provided upstream of the hinge portion. And a fixed portion fixed to the downstream side of the hinge portion, and when the jet engine is restarted,
By rotating the movable part, a flow ratio of the fan flow and the core flow is adjusted, thereby providing a restart device for a jet engine.

According to the configuration of the present invention described above, the stationary blade is separated into the movable portion and the fixed portion, so that the flow rate of the fan flow can be adjusted by the movable portion, and the fan flow is controlled by the fixed portion. Can be rectified.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. Note that the same reference numerals are given to portions common to the related art, and description thereof will be omitted.

FIG. 1 is a view showing a jet engine restart apparatus according to the present invention. FIG. 1 (A) is an overall configuration diagram of the jet engine, and FIG. 1 (B) is a view of a portion A in FIG. It is a part of the developed view. A jet engine 1 shown in FIG. 1A has a core having a compressor 3 (a low-pressure compressor 3a and a high-pressure compressor 3b), a combustor 4 and a turbine 5 (a high-pressure turbine 5a and a low-pressure turbine 5b);
Outer duct 9 serving as an outer shell, and fan 2 on the upstream side of core portion
A substantially cylindrical partition wall 10 that separates the air taken in from the core flow into a core flow 7 passing through the core portion side and a fan flow 8 passing through the outer duct 9 side, and the fan flow 8 provided between the outer duct 9 and the partition wall 10 to make the fan flow 8 an axial flow And a stationary blade row 12 for rectification. And, the restarting device of the present invention is shown in FIG.
As shown in (B), each stationary blade 12s of the stationary blade row 12 includes a hinge portion 13 extending in the radial direction of the jet engine 1,
It comprises a movable portion 14 rotatably provided upstream of the hinge portion 13 and a fixed portion 15 fixed to the downstream side of the hinge portion 13. The movable portion 14 is moved from a position (reference position) indicated by a solid line that forms a wing shape together with the fixed portion 15 (a reference position) to a position indicated by a broken line where the tip of the movable portion 14 and the hinge portion 13 are substantially on the same circumference (re-position). (Starting position), and can be fixed at a desired position.

The operation of the jet engine restart apparatus of the present invention in an aircraft equipped with the above-described jet engine will be described with reference to FIGS. FIG. 2 is a diagram showing the relationship between the flight speed of the jet engine, the bypass ratio, and the ignitable area of the combustor. The vertical axis is k / bypass ratio, the horizontal axis is the flight speed, and the shaded portion indicates that the combustor is ignitable. The area and the downward-sloping straight line indicate the lower limit of the ignitable area of the combustor.

During normal flight of the aircraft, the stationary blades 12s
It is assumed that the movable portion 14 is at the reference position in FIG.
It is assumed that the user is flying at the flight speed indicated by point A in FIG.
At that time, if for some reason the combustor 4 of the jet engine 1 unintentionally extinguishes fire or performs a stop operation due to an abnormality, the flight speed gradually decreases as shown in FIG. The jet engine 1 moves to an area (for example, a point B) protruding from the ignitable area. In order to bring the jet engine 1 to the ignitable region again, it is the quickest and most effective means to move the point B directly above the ignitable region (for example, the point C) by lowering the bypass ratio. It is considered to be. Therefore, FIG.
As shown in (B), if the movable portion 14 of the stationary blade 12s is rotated around the hinge portion 13 to the restart position shown by the broken line, even if the amount of air taken in from the fan 2 is the same, The flow rate of the fan stream 8 can be reduced, and the flow rate of the core stream 7 can be increased. As described above, by reducing the flow rate of the fan flow 8 with respect to the core flow 7 (that is, reducing the bypass ratio), as shown in FIG. (Point C). Therefore, the jet engine 1 can be restarted even at a low flight speed as indicated by the point B, and a stable flight can be restarted. Further, in the above description, the case where the jet engine 1 protrudes from the ignitable region, such as point A → point B → point C, has been described. However, if the restart device of the present invention is used, the By adjusting the rotation angle of the movable portion 14 to correspond to the flight speed, the bypass ratio is adjusted so that the jet engine 1 does not always protrude from the ignitable region (ie, is moved linearly from the point A to the point C). Control).

The jet engine restart apparatus of the present invention described above adjusts the flow ratio between the fan stream 8 and the core stream 7 so that the combustor 4 can be re-ignited even at a low flight speed. 1 shows one embodiment for realizing a method of restarting the jet engine 1. Further, as shown in FIG. 1 (B), the restart device of the jet engine 1 of the present invention has the fixing portion 15 and thus has the function of rectifying the flow direction of the fan flow 8 in the axial direction. I have. Furthermore, depending on the flight conditions of the aircraft,
Since the flow direction of the air taken in from the fan flow 8 fluctuates, even during the flight, the movable portion 14 of the stationary blade 12s follows the flow direction of the air, so that the fan flow 8 can be rectified to the axial flow without waste. Can also.

As a restarting device for the jet engine 1, although not shown, the movable portion 14 and the fixed portion 15 of the stationary blade 12s are integrated, and the entire stationary blade 12s is rotated about the hinge portion 13 as an axis. Alternatively, a stationary blade row for rotating the entire stationary blade 12s may be separately provided on the upstream side of the conventional fixed stationary blade row.

The present invention is not limited to the above-described embodiment, but may be applied to a type in which the core stream 7 and the fan stream 8 join on the way, without departing from the gist of the present invention. Of course, various changes can be made.

[0018]

According to the above-described method and apparatus for restarting a jet engine according to the present invention, the flow ratio between the fan flow and the core flow can be adjusted. Since it does not protrude from the ignition region, the combustor can be re-ignited, and the jet engine can be restarted. Further, by separating the stationary blade into a movable portion and a fixed portion, there is an excellent effect that the fixed portion can rectify the fan flow into an axial flow.

[Brief description of the drawings]

FIG. 1 is a view showing a restart device for a jet engine according to the present invention, wherein FIG.
(B) is a part of a development view of part A in FIG. 1 (A) as viewed from the outside in the radial direction.

FIG. 2 is a diagram showing a relationship between a flight speed of a jet engine, a bypass ratio, and an ignitable region of a combustor.

FIG. 3 is an overall configuration diagram of a jet engine.

FIG. 4 is a diagram illustrating a relationship among a flight speed of a jet engine, a bypass ratio, and an ignitable region of a combustor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Jet engine 2 Fan 3 Compressor 3a Low pressure compressor 3b High pressure compressor 4 Combustor 5 Turbine 5a High pressure turbine 5b Low pressure turbine 6 Tail cone 7 Core flow 8 Fan flow 9 Outer duct 10 Partition wall 11 Stator blade row 12 Stator row 12s Static Wing 13 Hinge part 14 Movable part 15 Fixed part

Claims (2)

[Claims] 1. A core flow having a compressor, a combustor, and a turbine, an outer duct serving as an outer shell, and a core flow passing air taken from a fan upstream of the core portion through the core portion and a fan flow passing through the outer duct side. A method of restarting a jet engine, comprising: a substantially cylindrical bulkhead that separates into a plurality of airflows; and a stationary blade row that is provided between the outer duct and the bulkhead and rectifies a fan flow to an axial flow. Adjust the flow ratio of the fan flow and the core flow according to the flight speed,
A method for restarting a jet engine, comprising re-igniting the combustor. 2. A core flow having a compressor, a combustor, and a turbine, an outer duct serving as an outer shell, and a core flow passing air taken from a fan upstream of the core portion through the core portion and a fan flow passing through the outer duct side. And a stationary blade row provided between the outer duct and the partition wall for rectifying a fan flow to an axial flow. The wing includes a hinge portion extending in the radial direction of the jet engine, a movable portion rotatably provided upstream of the hinge portion, and a fixed portion fixed to the downstream side of the hinge portion, A restart device for a jet engine, characterized in that when the jet engine is restarted, the movable part is rotated to adjust a flow ratio between the fan flow and the core flow.